JP5702703B2 - Evaluation device for concrete connection surface - Google Patents

Description

  The present invention relates to a concrete joining surface evaluation apparatus.

When constructing a concrete structure such as a dam, when a new concrete is placed in contact with the surface of the already hardened concrete, the contact surface is called a joining surface.
The hardened concrete surface is roughened with a wire brush or high-pressure water so that the joint surface does not become a weak point of the structure.
As a standard for determining the degree of roughening, the construction person and the inspector confirm the situation of the same joint surface treatment in advance and take a picture.
The enforcer performs transfer surface processing based on the photograph, undergoes witness inspection by the inspector, and makes judgments using expressions such as “deep”, “Asama”, and “optimum”.

Japanese Patent Application Laid-Open No. 2008-145174.

Since the evaluation of the conventional concrete joining surface as described above is subjective, there is a problem that the judgment is likely to be arbitrary and the quality may vary.
Another problem is that the apparatus and analysis method are complicated and expensive.
Particularly in dam concrete, since the quality of the joint surface treatment greatly affects the integrity, water density, and strength, a simple and objective determination method is required.

In order to solve the above problems, the concrete joining surface evaluation apparatus of the present invention is an apparatus for evaluating a joining surface in which new concrete is placed on the surface of concrete placed in advance. It is composed of a line laser, a digital camera, and a personal computer for analysis, and a line-shaped laser beam is irradiated onto the concrete joint surface so as to form a straight line irradiation line in a plan view , and the irradiation line is photographed from an oblique direction with a digital camera. The joining surface is extracted as coordinate data by image analysis.
Furthermore, the method for evaluating a concrete joining surface of the present invention uses the above-described evaluation apparatus, and irradiates the joining laser with a line laser so as to form an irradiation line in a straight line in plan view, and the irradiation line is photographed from an oblique direction. Then, the lens of the captured image is corrected, the width of the irradiation line subjected to the lens correction is averaged to extract the average irradiation line, and the waviness curve included in the average irradiation line is extracted by a filter and removed. It is characterized by extracting a roughness curve and numerically evaluating the roughness curve.

Since the evaluation device and method of the concrete joint surface of the present invention are as described above, at least one of the following effects can be obtained.
<1> Since it is possible to measure the concavo-convex shape of the concrete joint surface and numerically evaluate the degree of concavo-convexity from the measured value, unlike the conventional subjective judgment of the person in charge, a very objective evaluation It can be performed.
<2> The constituent parts are commercially available and inexpensive, and are simply a combination of them, so that they are simple and economical and easy to maintain.
<3> If the line laser and digital camera are installed on a fixed frame, the distance and angle between the joining surface and the digital camera can be maintained at any site, so fine adjustments can be made to the installation of the device. It is unnecessary and can be evaluated quickly by installing an evaluation device.

Explanatory drawing of the Example of the evaluation apparatus of the concrete joint surface of this invention. Explanatory drawing of the Example for performing lens correction. Explanatory drawing of the state before and behind lens correction. Explanatory drawing which extracts an average irradiation line from a wide irradiation line. Explanatory drawing which extracts a roughness curve from a synthetic curve. Explanatory drawing of roughness numerical evaluation of a joint surface. Explanatory drawing of the state which attached the apparatus to the mount frame. Explanatory drawing of the state which arises in a coordinate system at the time of imaging | photography.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

<1> Target of evaluation As described above, the evaluation device for the concrete joining surface of the present invention is a device for evaluating the joining surface in which new concrete is placed on the surface of the concrete placed in advance. is there.
The connecting surface is not limited to a horizontal plane, and a vertical surface can be measured and evaluated.

<2> Basic Configuration The apparatus of the present invention includes a commercially available line laser 1, a digital camera 2, and a personal computer 3 for analysis.

<3> Line Laser A commercially available line laser 1 can be used.
This line laser 1 is a device that can spread a linear laser beam into a fan shape by passing it through a lens, transform it into a thin line beam, and irradiate it onto the concrete joint surface 4.
When this line laser 1 is irradiated onto the concrete joining surface 4, one linear irradiation line 41 can be formed on the surface of the joining surface 4.

<4> Digital Camera As the digital camera 2, a commercially available digital camera 2 can be used as it is.
With this digital camera 2, the irradiation line 41 irradiated on the joining surface 4 can be photographed and input as data to the analysis personal computer 3.

<5> Lens Correction As shown in FIG. 8, in order to shoot with the digital camera 2 from the licking direction when defining the XYZ axes, deviations such as X ′, Y ′, and Z ′ are present in the coordinate system of the shot image. Arise.
For this reason, the height of the image data does not match the height of the unevenness on the surface of the actual joint surface 4.
Therefore, as shown in FIG. 2, the coordinate reference plate 5 is set up on the same cross section as the line laser 1, and photographing is performed in a state where the reference plate 5 is reflected in the image.
As the coordinate reference plate 5, for example, a lattice plate in which a large number of rectangles and squares in which XY coordinate lines are crossed at right angles can be used.
If the reference plate 5 is photographed from an oblique direction, a distorted grid appears as image data. (Figure 3 left)
By performing image processing so that the lattice is an accurate rectangle or square, it is possible to correct lens aberration and coordinate system deviation. (Figure 3 right)
Such correction can be performed using commercially available software.

<6> Averaging of irradiation line Since the laser beam has a thickness, the irradiation line 41 irradiated with the line laser 1 also has a certain width. (Fig. 4)
Therefore, it is necessary to extract the average value as a representative value.
The method will be described below.
First, since the image data is a set of M × N pixels, the irradiation line 41 can be expressed by a two-dimensional orthogonal coordinate system.
When the image of the irradiation line 41 is defined as shown in FIG. 4 with the X axis and the Y axis, the value of Yn at an arbitrary point Xn is the width of the maximum value (Ynmax) and the minimum value (Ynmin) according to the width of the laser line. Will have.
Therefore, in order to digitize the irradiation line 41 having such a width, an average value is taken to obtain the average irradiation line 42.
That is, the average irradiation line 42 is determined as Yn = (Ynmax + Ynmin) / 2.

<7> Extraction of Roughness Curve The average irradiation line 42 extracted by averaging the thick irradiation line 41 includes not only irregularities due to the aggregate but also curves due to the waviness of the joint surface at that stage.
That is, the average irradiation line 42 is a composite curve of a “roughness curve” due to the unevenness of the aggregate and a “waviness curve” due to the waviness of the joining surface. (Upper figure of Fig. 5)
However, since the object of the present invention is a method for evaluating the unevenness of the aggregate, the undulation curve is unnecessary and it is necessary to remove it from the composite curve.
Therefore, only the waviness curve is extracted from the composite curve by a low-pass filter, and this is subtracted from the composite curve and removed. (Bottom of Fig. 5)
In this way, only the roughness curve obtained by removing the waviness curve from the composite curve can be taken out.
Here, the low-pass filter is a type of filter circuit, which is a filter that passes low frequencies well and does not pass a band of frequencies higher than a certain cut-off frequency.
The cutoff frequency in that case can be arbitrarily selected by the filter designer, and therefore many types of filters are commercially available that are useful for removing high-frequency components that do not need to be included in the signal.
Thus, the roughness curve extracted from the irradiation line 41 is converted into coordinate data.
Data converted into coordinate data can be applied to, for example, a surface roughness index defined in JIS B0610 to evaluate the surface unevenness numerically.

<8> Fixed frame The above-described line laser 1 and digital camera 2 are attached to the fixed frame 6.
As this fixed frame 6, for example, a pair of frame bodies 61 that open in an A shape can be installed facing each other, and a gate-type frame body in which the tops of both frames are connected by a horizontal member 62 can be used.
The line laser 1 and the digital camera 2 are attached to appropriate portions of the horizontal member 62.
Then, it can be installed so that the distance and angle between the joining surface 4 and the digital camera 2 are always constant.
Therefore, when the measurement is started, since the installation is completed simply by placing the fixed frame 6 of the measuring device on the concrete joining surface 4, the measurement work can be started immediately.

<9> Evaluation Method The order of the above evaluation methods will be described again. First, a frame including the line laser 1 and the digital camera 2 is installed on the concrete joining surface 4 to be joined.
Then, a line-shaped laser beam is irradiated from the line laser 1 onto the concrete joining surface 4 to form an irradiation line 41 in a straight line state in plan view.
The irradiation line 41 is photographed with the digital camera 2.
First, the lens correction of the shooting data is performed.
Next, the average irradiation line 42 is extracted by averaging the widths of the wide irradiation lines 41.
Since this average irradiation line 42 also includes a “waviness curve”, the waviness curve is extracted and removed by a low-pass filter, and only the roughness curve is taken out as coordinate data.
Through such an analysis process, the irradiation line 41 irradiated from the line laser 1 is converted into coordinate data as shown in FIG.
Data converted into coordinate data can be applied to, for example, a surface roughness index defined in JIS B0610 to evaluate the surface unevenness numerically.
Thus, according to the present invention, it has become possible to objectively evaluate the concrete surface, which has conventionally been subjectively determined.

Claims (3)

A device for evaluating a joining surface for placing new concrete on the surface of concrete placed in advance,
Consists of a line laser, a digital camera and a computer for analysis.
Irradiate the concrete joint surface with a line-shaped laser beam so as to form a linear irradiation line in plan view ,
Take a picture of the radiation from a diagonal direction with a digital camera,
Extract the joint surface as coordinate data by image analysis,
Evaluation equipment for concrete joint surface. The line laser and digital camera according to claim 1 are fixed to a fixed frame,
Configured so that the distance and angle between the joint surface and the digital camera can be always fixed,
Evaluation equipment for concrete joint surface. Using the evaluation device according to claim 1,
Irradiate the line laser to form a straight line irradiation line on the joint surface and photograph the irradiation line from an oblique direction .
Correct the lens of the shot image,
Average the width of the irradiation line that has been subjected to lens correction, and extract the average irradiation line,
The roughness curve is extracted by extracting the waviness curve included in the average radiation by a filter and removing it,
Perform numerical evaluation of roughness curve,
Evaluation method of concrete joint surface.

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